Stephen Mangan

as Nathan Sterne

as Arthur Conan Doyle

as Self - Guest

as Dirk Gently

as Sean Lincoln

as Self - Assistant, Self - Presenter

as Mason

as Rod Senseless

as Guy Secretan

as Television Executive #4

as Clown

as Bigwig / Black Rabbit of Inle / Shale (voice), Bigwig / Silverweed (voice)